<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>

  <script type="text/javascript">

    var num1 = 3;
    var num2 = 5;
    var result = num1 + num2;
    console.log(result);
    var str = '10';
    console.log(num1 + str);
    var result1 = num1 + parseInt(str);
    console.log(result1);

    </script>

</head>
<body>


</body>
</html>